
In Act 2, Scene 3, the friar is talking to his plants saying how they can be so wonderful but so poisonous at the same time.
"For this, being smelt, with that part cheers each part;
Being tasted, stays all senses with the heart." He's saying that if you smell some particulare kind of plant, it brings you pleasure, but if you eat it, then you'll die. There is no solid evidence that says that talking to plants benefits them. However, there is some truth to that because when you talk to a plant, you breathe on it, and plants need carbon dioxide to live.
Back in the day (1848), a German professor suggested in his book that plants were capable of feeling emotions, just like humans, and that you could promote healthy growth by showering your plant with attention. Another botanist guy said that plants may not be able to understand the spoken word, but they were capable of telepathically understanding the meaning of speech.
I thought this stuff was kinda weird, but it was still interesting. I just try to stay away from having my own house plants, because they generally end up dying. I guess I don't give them enough attention...lol.